Panel construction having a cellular core



June 24, 1958 E. wlNER PANEL CONSTRUCTION HAVING A CELLULAR CORE Filed Nov. 28. 1952 5 Sheets-Sheet l INVENTOR ATTORNEY Em. w.

June 24, 1958 E. wlNER PANEL CONSTRUCTION I-IVING A CELLULAR CORE 5 Sheets-Sheet 2 Filed Nov. 28, 1952 HGIILL. ELOQKS 'June 24, 1958 E. wlNER PANEL CONSTRUCTION HAVING A CELLULAR CORE Filed Nov. 2a, 1952 5 Sheets-Sheet 5 |"l mmmmmmmmm "In mmmmmmmm DEEEV mmmv EEEEEDV EEEEEEEV mm INVENTOR mmmmmmmmmm- V N mmmmmmmmmmmmv mmmmmmmmmmmmmv mmmmmmmmmmmmnw mmmmmmmmmmmg mmmmmmmmmmw mmm-Ummm@ K LA.) -QKS ATTORNEY June 24, 1958 E. wlNER 2,840,430

PANEL CONSTRUCTION HAVING A CELLULAR CORE Filed Nov. 28, 1952 5 sheets-sheet 4 ATTORNEY 5 Sheets-Sheet 5 June 24, 1958 E.w1NER PANEL CONSTRUCTION HAVING A CELLULAR CORE Filed Nov. 28. 1952 ATTORNEY 2,840,430V PANEL CONSTRUCTIORIAVlNG A CELLULAR Ephraim Winer, Baltimore, Md., assignor to The National .Plastic Products Company, Odentou, Md., a corporation of Maryland v Application November 28, 1952, Serial No. 322,906

21 claims. (c1. 311-106) The present invention relates to a panel construction. More particularly, the present invention relates to a panel construction in which a thermoplastic molded core is incorporated therein.

Prior to the instant invention, in the production of laminated panels and more specifically table tops, it was the usual practice to employ a wood or plywood core to which was securely glued or fastened a thermoset laminated plastic top skin and a bottom laminated sheet. The construction was finished otf by trimming the edges with metal trim or plastic edging. Although these heretofore known table tops had desirable qualities, such as being waterproof and ywarp-proof, they were found to be undesirable from several viewpoints. One objection to these heretofore known table top constructionswas that the wood core prohibitively increased the weight of the panel and, consequently, vthe, table. Moreover, the procedure employed in cutting and fitting the wood core to the skin and applying the trimming to the edges was not only expensive, but time-consuming. v

It is an object of the present invention to provide a panel that incorporates a molded cellular core construction therein.

Another object of the present invention is to provide a panel in which the edges thereof are formed integral with the molded core construction. y

Still another object of the present invention is to provide a panel construction incorporating the cellular core whereby the panel construction is utilized as a table top.

Still another object of the present invention is to provide a table top in which the edges are formed by inserting a block into a molded core, the block having a thermoset laminated edge .secured thereto. f

Still another object of the present invention is to provide a panel construction incorporating the cellular core whereby the panel construction is 'utilized as afkitchen cabinet front. V- f Still another object of the present invention is to provide a panel construction 'incorporating the cellular core whereby the panel construction is employed' in a4 door assembly,

Other objects 4and the naturel and advantagesof the instant invention will be apparent from thefollowing description taken in conjunction with the accompanying' drawings, wherein: y p

Fig. 1 is a plan view with parts broken away of a table top embodying one form of 'the present invention; Fig. 2 is a section taken along the line 2-2 of Fig. 1; Fig. 3 is a section taken along the line 3-3 of Fig. l;

Fig. 4 is an enlarged view of a corner construction of'.

the table top illustrated in Fig. 1;

Fig. 5 is a plan view with parts broken away of a' table top embodying a modification ofthe present invention' y v Fig. 6 is a'view taken along the line 6-6 of Fig. 5;

Fig. 7 is a view taken along the line 7 7 ofFig.` 5;

Fig. 8 is an enlarged view of a corner construction of" the table top shown in Fig. 5;

2,840,430 Patented June 24, .195s

Fig. 9 is a perspective View of an injection molded core', utilized for the corners in the table top construction illustrated in Fig. 1; Y

Fig. 10 isa perspective view of an injection molded core utilized for the middle section in the tabletop construction illustrated in Fig. 1;

Fig. 11 is a perspective view'of an injection molded core employed in the table top construction illustrated in Fig. 5;

Fig. 12 is a plan view of a modied table top construction which incorporates the molded cores illustrated inv Figs. 9, 10 and 1l;

Fig. 13 is a vertical sectionalv view of a portion of another modified form of the present invention; .d

Fig. 14 is a perspective. view of a frame member util- A ized in the modiiication shown in Fig. 13;

areinjection molded into the Ysquare configurations.

,Fig. 15 is a view showing a portion of a block from which the frame members shown in Fig. 14 are cut;

Fig. 16 is a plan view-of a table top with parts broken away, illustrating a complete one-piece core construction;

Fig. 17 is a plan view of a molded sheet of core material; f

Fig. 18 is a vertical sectional view ofA a modified form of panel construction with a laminate applied to the flat surface of the core structure; and

Fig. V19 is a vertical sectional view of a panel construction for use as a kitchen cabinet front.

Referring to the drawings, and particularly Figs. 1-4, one form of the .table top construction embodied in the present invention is illustrated. The table top shown in Fig. l is indicated generally at 10 and includes a plurality of square-like cores joined togethenas will hereinafter be described, to form a table top assembly having a rectangularv configuration. cores comprisingthe table top assembly include corner cores 12V and middle cores 14 positioned between the corner cores 12. The cores 12 and 14 illustrated in Fig. 1 may be formed from any suitable materialjbut are.

preferably formed from a thermoplastic material andi It:

will be apparent from the description hereinafter that the cores 12, 14 have the same general construction," differing only in the arrangement of the outside side walls.

Referring to Fig. 9, a corner core 12 is illustrated therein and is shown comprising a molded unit having a cellular body. As shown in Figs. 2 and 3, the cellular body of the core 12 includes a bottom sheet 16 which has integrally joined thereto a series `of vertical walls 18. As seen in Fig.I 4, the-vertical walls 13 extend obliquely and cross oneanother at right angles` to form with the` bottomV sheet 16 a series of hollow cells or cavities. Enclosing and extending around the square cellular body ofthe core section 12 are end walls 20 which are joined integrally to adjacent vertical walls 18 and the bottom sheet 16. The bottom sheet 16 of the core 1.2 extends outwardly from the endY walls 20 to. form a'shelf 22,r

around-the cellular bodyLthepurpose of which will hereinafter be described.- Integrally joined to the shelf 22 at right angles thereto along'the sides of the core 12 facingr Vnormally associated with table tops.` As shown in Fig. i the' side wall 28 extends around only the outside edges As shown in Fig. 1, the

1 3 of the core `12 and thereby top 10 when all of the cores are in the assembled position. Asagain shown in Fig. 9, the side wall 28, the verticalwall` 24 `and bottom portion 26 depend below the bodyofthe corej12; It is apparent that when Athejcores areV assembled togethertFig. l), the depending portion ofthe cores will form an apron around the tabletop.

Referring now, toA Fig. 10, a `middle core 14 is' illustrated and comprises a square thermoplastic molded unit formed by injection molding vhaving a vcellular body Whichissimilar in construction to the cellular, body of the `core ;12 described hereinabove. is adapted `to be positioned between the corner cores12, as illustrated in Flg.`1 and, therefore', only one side of the core 14 will face along the'outer margin of the table top10. Consequently, the short vertical wall 24, bottom lportion 26 and side wall 28 are only formed on the `edge of the middle core 14 that faces along the'outer margin of the table top 10. u Y

`In assembling the table top ,10 illustrated in (Fig. l,` the corncrrcores 12 are placed in theV corner'positions and the `middle cores 14 are placed therebetweenf With the cores 12, 14 `in this position, the side wall 28 k'extends continuously around the outer margin of the table top 10 and defines the outer edge thereof. In order to secure the cores in the assembled position, elongated wood fills or frame members 30k areA provided `which extend ,the length of the` table top 10 and similar frame members d 32 are provided which extend the width Vof the table top 10. As shown in` Figs. 1 and 2*, the frame members 30 and 32 are L-shapcd, one side of the LV fitting snugly t in the channel defined by thesideiwall 278V andthe vertical Vwall 24, and the other side 'of the L` engaging the shelf 22. The members 30, 32.completely fill the space betweenthe side wall` 28 and thejend wall 20yo'f1the'cellular body and not `only aid inthe assembly of the cores 12, 14 butactto reinforce thecoresr12, 14. in the assembled position. The ends of the members 30, y32 are rounded' to engage the rounded corners of thel side wall 28 ofthe core 12 and are cut angula'rly so that a snug tit may be Veffected at .the corners of the assembly. The members 30, 32 are also formed so that they extend only tothe top level'of the side wall 28 and the cellular body and thereby define with the cellular body a level sur face for receiving `a suitable top. Additional wood fills or frame members 34, 36 are provided for the inner margins of the` cores 12 and 14 and are adapted to aid in. rmly securing the cores in position.` The elongated member 34 is positioned between the adjacent cores 12, 1,4 and extends the length of the table top 10, being limited by the members 32. The smaller wood fills or frame members 36 connect the inner margins of the core sectionsl 12, 14 and are limited by the elongated members 30 and 34.` As shown in Fig. 3, it is apparent that the members 34 andy 36 require a rectangular cross section since they are adapted to engage Vonly the shelves 22 of adjacent cores. The members 34 and 36 also extend to the top level of the cellular body of the adjacent cores 12, 14 and thereby present withthe cores 12, 1 4 and members 30, 32 a completely level surface'. All ofthe frame members are secured to the cores 12, 14 by a suitable resin adhesive which not only waterproofs the adhering joints, but reinforces the assembly.

With the cores 12, 14 `in the` position shown in Fig. 1, a top 38 having a rectangular configuration which is determined `by the assembly of the cores 12,` 14 is placed overY the lassembled cores. The top 38 is formed from paper which has been laminated together, impregnated with a thermoset` plastic material and compression molded with any desirable `design formed therein. The table top assembly is then completed by applying a suitable adhesive between the top 38 and the cores 12,114 and frame Referring how to Figs.V 4-8 and 11, a modification of defines the edging of the table i The middle 1- core l 14.

the invention is illustrated and comprises a table top indicated generally'in Fig. 5 at 40. The table top 40 includes a plurality of molded thermoplastic cores 42 which, as shown in Fig. ll, are injection molded in a single unit and are similar in construction to the cores 12 and 14 described hereinabove. Each core 42 includes a cellular body defined by a. bottom sheet 44 and a plurality of obliquely extending vertical walls 46 and end walls 48 joined integrally to the bottom sheet 44. The core 42 is completed by extending the bottom sheet 44 outwardly from the cellular body to define a shelf 49. In the assembled position shown in Fig. 5, the cores 42 are secured together by elongated frame members 5l) and `42 to the frame 52.

52 which are arranged to form the margins of a rectangle, their ends being rounded and angularly cut. It is apparent that when `the frame members 50, 52 are assembled, the rounded ends of the frame members Si), 52 will combine to form the rounded edges of the table top corners. Referring to Fig. '6, a core 42 is shown secured to the frame member 52, the shelf 49 extending into a kerf or groove 53 provided along the interior edge of the frame member 52. The frame member 52, which depends below the body of the core 42, not only serves to reinforce the table top construction, but also provides a means for receiving an edging 54 thereon, and furthermore serves as an apron for the table top. The edging 54 is of extruded T section and may be formed from metal such 4as aluminum, but is preferably formed from a thermoplastic material. The edging 54 includes a leg 56 which is forced into `the frame member 52 and thereby secures the edging thereto. VPins 58 are hammered into the underside of the frame 52, extending through the shelf 48 and the leg 56 and thereby firmly securing the edging 54 and core It is apparent that the cores 42 and edging 54 are secured to the frame members 50 in the manner described above with respect to the frame member 52.

In order to secure the inner margins of the cores 42 in the assembled` position, a middle elongated frame member 60 and short inner frame members 62 are provided. The middle frame member 60 extends the length of the table top 42 and receives the shelves 49 of the cores 42 in an appropriate kerf or groove. Referring to Fig. 7, an inner frame member 62 is shown secured between two adjacent cores 42 and has formed therein kerfs 64, 66 for receiving the shelves 49 of the adjacent cores 42. Pins 58 are secured in the underside of the frame member 62 and firmly connect the cores 42 thereto. g

Prior` to the, application of the edging 54 and with the cores 42 secured together by the frame members 5,10, 52, 60, 62 a top member 63 of laminated paper, whichhas been impregnated with thermosetting resin and compression molded into a plastic sheet is placedv forma square table top. The table top assembly 70 includes the `corner cores 12 andmiddle core 14, which are secured in position and define the table top outer margin. The edges along the outer margin of the table top 70 are formed by the side wall 28 which is integralhy joined to the outwardly extending shelf 22 of the cores 12,v 14, as hereinabove described. Isolated` from the outer table top margin and positioned in the center `of the assembly is a core 42. As shown in Fig. 12, the core 42 is completely surrounded lby the cores 14 and is shaped frame members 30 and `3,2.for securing` the cores.`

12, 14 in position, while inner frame vmembers having a cross section similar to frame member 36 are secured to the cores 14 and 42, as described hereinabove. A suitable top sheet 72 is placedover the cores and secured thereto by applying a suitable adhesive and the necessary pressure. lt is apparent that any size table top can be constructed by using a combination of the cores 12, 14 and 42. A rectangularr and square'conliguration using six and nine cores, respectively, are illustrated, but other table tops using morexor less cores are contemplated and are within the scope of the present invention.

Referring now to Figs. 13, 14 and 15, a further modification of the present invention is illustrated and includes a core indicated generally at `80. The core 80 is formed with a cellular body as hereinabove discussed and includes cavities defined by vertical walls 82, an end wall 84 and a bottom sheet 86. The bottom sheet 86 extends into aishelf portion 88 which in turn has formed integrally therewith a vertical and horizontal wall comprising a stepped portion 90. Engaging the stepped portion 90 and the shelf portion 88 is an Lj-shaped Ywood fill or frame member 92 which forms the margin around the table top. The member 92 is preformed with an edge 94 which is formed of paper sheets impregnated with a thermosetting plastic and compression molded.Y

The laminated edge 94 is securedto the member 92 as will hereinafter be described, and is fixed in position on the stepped portion 90 and shelf 88 by a suitable adhesive. The innerextending shelf 88 of each of they cores 80 are suitably secured tojframe members and the assembly is completed by a top member 96 formed of a laminated material which is secured to the cores 80 by a suitableadhesive and application of pressure.

In forming the member 92,'it is desirable to form an edge thereon that corresponds vto the material utilized on the top of the table. Since it is difficult to form narrow strips of laminated thermoset plastic material and then secure them to anedge, a sheet of the material, similar to the top sheet 96, is pressed onto a sheet of wood 98, a portion of which is shown in Fig. 15. The

sheet 98 with the plastic sheet adhered thereto is then cut into strips lengthwise, as indicated in Fig. l5, the result being a series of blocks as shown in full lines in Fig. 14. The frame member 92 is then formed by rabbeting out the blocks along the dotted lines shown in Fig. 14. The resulting member 92 is formed complete with the laminated edge 94 and -is easily'placed on the stepped portion 90 and shelf 88 of the table top 80, and secured thereto by a suitable resin adhesive.

The modification illustrated in Figs. 13, 14 and l5 incorporates a modified core 80 which includesY the stepped portion 90 joined to the shelf 88.' With this construction, it is necessary to utilize the L-shaped frame member 92. It is also contemplated to employk a core 42, such as illustratedin Fig. 11 and a frame member 52, such as illustratedin Fig. 6 with the technique discussed above with respect to the'preformed laminated edge. In this further modification, the frame member 52 is preformed with a thermoset laminated plasticstrip secured to the edge thereof, asshown in Figs. .14 and15 and-is kerfed to receive the shelf 48 of the core 42. The frame member 52 complete with the laminated edge 94 Vis then placed in position engaging the core 42 and the laminated top 64. It is apparent that by employing this latter procedure, the special core 80 is no longer required and the rabbetngtstep necessary to form the frame member to t the core is obviated. p

Referring noWl to Fig. 16, la panel construction generally indicated at 100.is illustrated and includes a core 102 of the type described above in connection with Figs. 1-4 and 9. The core 102 is vformed in a single piece structure of any desirable configuration and includes inner depending walls )104 and Aoutside `edges 106 which definel 6 v a channel for receiving frame meinb'ers'108r which, id turn, dene the outer margins of the panel. Thisconstruction is similar to the structure illustrated in Fig.j2. A laminated top 109 is'secured to the one-piece core and assembled members 108, and completes'the panel assembly; The onefpiece core 102 obviates the need of the inner frame 'members for securing individual core members together and enables'a complete panel' construction to be assembled with a minimum of time and effort. The panel construction illustrated in Fig. 16 is shown and described as being formedin a manner simi-y lar to the panel illustrated in Figs. 1-4 and 9. However,

itis apparent that apanel of the type shown in Figs. 5-8'y and 11 can also be formed in a one-piece construction.

Referring now to Fig. 17, a modified core construction is illustrated and comprises an extendedgmolded sheet 110 of core material. 'The core sheet 110 is adaptedV to be cut into suitable lengths for use in a panel construction such as a table top and can also be cut into the desired configuration, such as, for example, a rectangle, square or circle.

'in Fig. 17. The core is then assembled with the frame members and laminated top as described above.`

`Referring now to Fig. 18, a further modication of the panel construction is illustrated generally at 114 and comprises a molded cellular core which is dened by a 'sheet 116 and a plurality of vertical walls 118 formed integral therewith. The cellular core is shown in an inverted position, the cellular side facing downwardly. A shelf portion is formedintegral with the sheet 116 and is so constructed as to define a large surface for receiving a frame member 122. The frame member, lwhich is somewhat wider than that described hereinabove, is secured to the widened shelf portion 120 and the end wall ofthe cellular core and is adapted to have secured thereto a backing sheet 124. The backing sheet 124 forms the bottom of the panel construction 114 and is securely held in place by a suitable adhesive applied to the surface of the frame member 122. The panel assembly is com`V pleted by a laminated top 126 secured to the sheet`116 and an edging 128 secured to the frame member 122.

Only asection of'thepanel construction 114 is illustrated in Fig. 18, but it is understood that a table top or the like may be formed having a one-piece core such as illustrated above in connection with Fig. 16, or a plurality of cores may be joined together such as illustrated in Figs. 5-8.

AReferring now to Fig. 19, a panel construction indicated generally at 130 is illustrated and' is adapted to be utilized as a kitchen cabinet front, or the like. The panel construction 130 includes a molded cellular core which comprises a bottom sheet 132 and integral walls 134 forming cells or cavities therebetween. The bottom sheet 132 extends into a shelf portion 135 which receives thereon a frame member 136 reinforcing the core and forming the outer margin of the panel. A laminated top 138 is secured to the open celled side of the core and a suitable edging 140 is secured to the frame member 136, thereby completing the panel assembly. The bottom sheet 132 has a recess 142 formed therein, when the core is molded, which is adapted to receive one side of a hinge member'144. The other side of the hinge member 144 is suitably secured in a recess 146 formed in the side of the'kitchen cabinet. It is apparent that the panel construction 13.0 described above can be formed employ- The individual cores cut from the core sheet 110are adapted to be assembled with frame members *"7 ing alone-piece cellularcore.. However, it is also con templated tolform ftheLpane'l `with `a .plurality of cores jonedltogether as described above.

It, is apparent'from theforegoing Vthat the` panels constructed ink accordance with the present invention are not only light in weight, but ,are strong and durable,

p waterproof and warp-proof.` The molded cores are simple to manufacture, being injection molded, and require no Special'ttings or `attachments in assembling other `than the `frame members. The edges are either conveniently formed as a unit with the `cores or inserted individually on the` frame members. TIf itiswdesirable to utilize a thermoplastic edge, a strip may be secured to the frame members. However, if a more stylish table is desired, a laminated plastic edge may be preformed with aframe member,` the plastic edge corresponding` in color and design to the laminated top sheet of the table top.

, I twillbe obvious to those skilled in the art that various changes may be made without `departing from the spirit of theinvention and, therefore, `the invention is not limited to what is shown in the drawings and described in the specification, but only as indicated in the appended claims.`

inner frame` members engaging the inside edges of said cores, said inner and outer frame members securingsaid cores together, and a top member secured'to said cores and forming the upper surface `of said panel construction. I`

2. In a panel construction, a molded plastic core,..said core comprising a cellular body, shelf means formed integral with said body and extending outwardly therefrom, a short vertical wall joined integrally to said shelf means, a horizontal portion joined Vintegrally to the bottom-most portion l.of-said short `vertical wall andra side wall `joined integrally to said horizontal portion, said side wall and said short vertical wall defining a channel therebetween, a frame member having an l` shaped cross section disposed in said channel and engaging said shelf means, said frame member defining an outer margin of said panel construction, `a second framemembei having a rectangular cross section engaging the inner side of saidshelf means, thereby reinforcing said core, and a top member engaging said core and said frame members andi thereby defining the'upper surface of said panel construction. u i l 3. In a panel construction, a plurality of molded plastic cores, each of said cores comprisinga cellular body, said cellular body including a bottom sheet anda series of vertical walls formed integral with said bottom sheet, said bottom sheet projecting outwardly beyond said body to form a shelf-like portion, wall portions integrally joined to` said shelflike portion and defining therebetween a channel,'one 'of said wall portions forming the outer edge for said panel construction, a frame member disposed in each of said channels formed in said cores and definingl the outerfmargin ofsaid panel construction,additional frame members engaging said shelf-like portion at the inner side of said cores, saidframe members securing said `cores together and reinforcing said cores, and a top membersecured to said cores and said frame members and thereby defining the upper surface of said panel construction.: p

4. -Y In a tabletop, a plurality of molded plastic cores,

each of said cores comprising a cellular body, a bottom i sheetformed integral with said cellular body, said bottom sheet `extending outwardlyl from said body` to define a` said` integral portion including a short vertical wall and a sidewall, said short vertical wall and side wall defining a channel therebetween, means disposed in said channel andfengaging said shelf, 'said .means defining the outer marginsiof said table top and securing said cores together, and a top sheet member secured'to said cores and forming the upper surface of said table top.

`5. In a tabletop, a plurality of cores, each of said cores including a side4 wall integrally joined thereto, said side wall defining the edge of said table top, frame members engaging said side .wall and said cores and defining the outside margin of said table top, and top means secured to saidcores and frame members forming the upper surface of said table top.

6. In a table top as set forth in claim 5, wherein additional frame members having a rectangular cross section engage `the inner edges of said cores, thereby securing the adjacent cores together. f

7. In a panel construction, a plurality of cores, each of said cores having a cellular body and a shelf extending outwardly from saidcellular body, frame members engaging said shelf and defining the outer margin of said table top, said frame members having a groove formed therein for receiving said shelf, additional frame members having grooves formed therein, said additional frame members engaging the'inner edges of said cores and receiving the inner extension of said shelves in said grooves, thereby securing adjacent cores together, an edging secured to the outer surface of said first-named frame members and forming the edging of said panel construction, and a top member secured to said cores and forming the upper surface of said panel construction.

8. In a table top, a core having a cellular body, said cellular 4body including a bottom sheet and a plurality of vertical walls formed integral with said bottom sheet, said bottom sheet extending outwardly from said cellular body to form a shelf, a frame member having a groove formed therein engaging said core, said frame member forming the outer margin of said table top, said groove receiving said shelf therein' for securing said frame member Yto said core, an edging secured to the outside surface of said frame member, and a top sheet secured to said core and defining the upper surface of said table top.

9. In a table top, a core comprising a cellular body and a shelf formed integral with said cellular body and extending outwardly therefrom, elongated frame members engaging said shelf and said cellular body and forming the outer margin of said table t'op, edging means secured to said frame `members and forming the edging for said table top, and a top member secured to said cellular body and said frame membersVV and forming the upper surface of said table top. Y

10. In a table top, a` core comprising a cellular body, a shelf portion formed integral with said cellular body andvextending outwardly therefrom and a stepped portion formed integral with said shelf portion, a frame member engaging said shelf portion and said stepped portion and defining the outer margin of said table top, said frame member Ihaving secured thereto a'laminated plastic edge, and a top member secured to said core and frame member and formingthe upper surface of said table top.

ll. In a table top, a core having a body and a shelf portion formed integral` with said body and extending outwardly therefrom, an I V-shaped frame member having a laminated strip of plastic secured thereto, said frame member engaging said shelf portion and forming the outer margin of said'table top, said laminated edgeof said frame member defining the outer edge of said table top, and a top member secured to said core and said frame member and forming the upper surface of said table top.

l2. In a table-top, amolded plastic core having a cellular b'odypand formed with a projecting shelf, a downwardly projecting apron'formed integral with said shelf andV including a side wall, said side wall forming the edge of said table top, and a top member covering said core and forming the Aupper surface of said table top.

13. In a table top, a core formed with an end wall and a projecting shelf and having a plurality of cavities formed therein, a frame member engaging said shelf and said end wall, said frame member depending below said core to form an apron, an edging formed around said frame member and secured thereto, and a top member secured to said core and frame and forming the upper surface of said table top.

14. In a panel construction, a one-piece molded core lcomprising the body of said panel construction, said body being formed in a cellular structure deined by a bottom sheet, a series of vertical walls formed integral with said bottom sheet and end walls, said bottom sheet extending beyond said end walls and defining ashelf for receiving frame members, said frame members engaging said end walls and forming the outer margins of said panel construction, and a top laminated sheet secured to the top of said core and frame members and forming the upper surface of said panel construction.

15. In a panel construction, a one-piece molded core comprising the body of said panel construction, said one-piece molded core being formed from an extended sheet of molded core material, said body defining a cellular structure and including a bottom sheet and a series of vertical walls and end walls formed integral with said bottom sheet, a shelf being formed integral with said bottom sheet and extending outwardly from said end walls, frame members engaging said end walls and shelf and forming the outer margins of said panel construction, and a top laminated sheet secured to the top of said core and frame members and forming the upper surface of said panel construction.

16. In a panel construction, a molded plastic core, said core comprising a cellular body, said cellular body including a flat sheet and a plurality of vertical walls formed integral with said flat sheet, said at sheet projecting outwardly beyond said cellular body to form a shelf, a frame member engaging said shelf and reinforcing said core, and forming a margin for said panel construction, a backing sheet secured to the open-celled side of said core and to said frame member, and a laminated sheet secured to said at sheet and forming the upper surface of said panel construction.

17. In a door construction, a molded plastic core comprising a cellular body, said cellular body including a at sheet extending into a shelf portion, a frame member engaging said shelf portion and reinforcing said core, a backing sheet secured to the open-celled side of said core and to said frame member forming one side of said door, and a laminated sheet secured to said iiat sheet and forming the other side of said door.

18. In a kitchen cabinet, a door construction including a molded plastic core, said core comprising a cellu- 10 lar body, said cellular body including a bottom sheet extending into a shelf portion, said shelf portion having a recess located on the underside thereof, said recess being formed inthe molding process, a frame member engaging said shelf portion and reinforcing said core, a top laminated sheet secured to the open-celled side of said core and to said frame member thereby forming therfront of said door, an edging secured to the outside edge of said frame member and forming the outerV edge of said door, and hinge means fitting into said recess and secured to said core member, said hinge means being operatively connected to said kitchen cabinet thereby permitting hinged movement of said door with respect to said kitchen cabinet.

19. In a kitchen cabinet, a door construction comprising a molded plastic core formed with a cellular body, a shelf portion formed integral with said body and extending outwardly therefrom, said shelf portion having a recess located therein adapted to receive a hinge, a reinforcing member engaging said shelf portion and a laminated sheet secured to the open-celled side of said core and to said reinforcing member, thereby defining the front of said door.

20. In a panelconstruction, a core comprising a bottom sheet and a series of vertical walls formed integral with said bottom sheet, said bottom sheet and vertical walls defining a cellular body, said bottom sheet projecting outwardly beyond said cellular body to form a shelf-like portion, wall portions integrally joined to said shelf-like portion and defining a channel therebetween, one of said wall portions forming the outer edge of said., panel construction, a frame member positioned in said channel for reinforcing said core, and a top member secured to said core and said frame member and defining the upper surface of said panel construction.

21. In a panel construction, a molded cellular body, the bottom of said cellular body projecting outwardly to form a channel, the outer wall of said channel dening the outer edge of said panel construction, means positioned in said channel for reinforcing said cellular body, and a top member secured to said cellular body and said reinforcing means and defining the upper'surface of said panel construction.

References Cited in the tile of this patent UNITED STATES PATENTS 2,096,908 Lytle Oct. 26, 1937 2,297,072 Raggio Sept. 29, 1942 2,444,183 Cahners June 29, 1948 2,477,852 Bacon Aug. 2, 1949 2,630,604 Marsh Mar. 10, 1953 FOREIGN PATENTS 429,301 Great Britain May 28, 1935 

